Atherectomy catheter drive assemblies

ABSTRACT

A drive assembly for driving an imaging catheter has a rotatable fiber and a rotatable drive shaft. The drive assembly includes a fiber optic rotating junction and a motor configured to rotate the rotatable portion of the fiber optic rotating junction. In some embodiments, the drive assembly includes a sensor configured to detect a rotational position of the fiber optic rotating junction and a processor configured to obtain the detected rotational position and stop the motor only when the fiber optic rotating junction is in a predetermined rotational position. In some embodiments, the motor includes a hollow shaft through which at least a portion of the fiber optic rotating junction extends.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Patent Application No. 61/646,843, titled “ATHERECTOMY CATHETERS WITH IMAGING,” filed on May 14, 2012. This application also claims priority to U.S. Patent Application No. 61/697,743, titled “BALLOON ATHERECTOMY CATHETERS WITH IMAGING,” filed Sep. 6, 2012. Both of these applications are incorporated by reference herein.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

BACKGROUND

A significant body of scientific and clinical evidence supports atherectomy as a viable primary or adjunctive therapy prior to stenting for the treatment of occlusive arterial disease. Atherectomy offers a simple mechanical advantage over alternative therapies. By removing the majority of plaque mass (debulking), a larger initial lumen is created. As a result, stent deployment is greatly enhanced. Moreover, there are advantages to atherectomy related to the arterial healing response. When circumferential radial forces are applied to the vasculature, as in the case of angioplasty or stenting, the plaque mass is displaced, forcing the vessel wall to stretch dramatically. This stretch induces injury which is a known stimulus for the cellular in-growth that leads to restenosis. By removing the disease with minimal force applied to the vessel and reducing the plaque burden prior to stent placement, large gains in lumen size can be created with decreased vessel wall injury and limited elastic recoiling. These effects have been shown to generate better acute results and lower restenosis rates.

Traditional atherectomy devices have been plagued by a number of problems that have severely limited market adoption of these devices. A significant concern in adopting these devices is that they tend to require the use of large, cumbersome, and expensive drive assemblies to control the rotation and/or axial translation of the atherectomy cutter. The drive assemblies described herein may overcome some of these hurdles.

SUMMARY OF THE DISCLOSURE

Described herein are drive assemblies for catheters having a rotatable cutter and on-board imaging.

In general, in one embodiment, a drive assembly for driving an imaging catheter has a rotatable fiber and a rotatable drive shaft. The drive assembly includes a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein. The drive assembly includes a first optical connection configured to connect the stationary fiber with a light source. The drive assembly includes a motor configured to rotate the rotatable portion of the fiber optic rotating junction. The drive assembly includes a second optical connection configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter. The drive assembly includes a sensor configured to detect a rotational position of the fiber optic rotating junction. The drive assembly includes a processor configured to obtain the detected rotational position and stop the motor only when the fiber optic rotating junction is in a predetermined rotational position.

This and other embodiments can include one or more of the following features. The sensor can be a slot sensor configured to detect a flat on the rotary optical junction. The drive assembly can further include a locking mechanism configured to lock a handle of the imaging catheter to the drive assembly. The locking mechanism can include mechanical features to physically align the handle with respect to the drive assembly. The locking mechanism can be configured such that physical alignment of the catheter handle with respect to the drive assembly can further align an optical connection of the handle with the predetermined rotational position of the fiber optic rotating junction. The stationary and rotatable fibers can be configured to transmit an optical coherence tomography signal.

In general, in one embodiment, a method of driving an imaging catheter having a rotatable fiber and a rotatable drive shaft includes connecting a stationary fiber of a stationary portion of a fiber optic rotating junction in a drive assembly with a light source; connecting a rotatable fiber of the fiber optic rotating junction with the drive shaft and the rotatable fiber of the imaging catheter; rotating the rotatable portion of a fiber optic rotating junction with a motor in the drive assembly such that both the drive shaft and the rotatable fiber of the imaging catheter rotate and such that light is transmitted from the light source to the rotatable fiber of the imaging catheter; sensing a position of the fiber optic rotating junction; and stopping the motor based upon the sensed position only when the fiber optic rotating junction is in a predetermined rotational position.

This and other embodiments can include one or more of the following features. Sensing the position can include sensing the position with a slot sensor. The method can include locking a handle of the imaging catheter into the drive assembly. The locking mechanism can include mechanical features to physically align the catheter handle with respect to the drive assembly. Locking the handle of the imaging catheter into the drive assembly using the mechanical features can align an optical connection of the handle with the predetermined rotational position of the fiber optic rotating junction. The method can further include transmitting an optical coherence tomography signal through the stationary and rotatable fibers.

In general, in one embodiment, a drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft includes a drive assembly housing. The drive assembly further includes a fiber optic rotating junction within the housing having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein. The drive assembly includes a first optical connection through the housing configured to connect the stationary fiber with a light source. The drive assembly includes a motor within the housing configured to rotate the rotatable portion of the fiber optic rotating junction. The drive assembly includes a second optical connection through the housing configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter. The housing is less than 75 cubic inches in volume, and the drive assembly has a total weight of less than 2 pounds.

This and other embodiments can include one or more of the following features. The volume can be less than 40 cubic inches. The volume can be less than 20 cubic inches. The drive assembly can further include a locking mechanism configured to lock a handle of the imaging catheter to the drive assembly. The stationary and rotatable fibers can be configured to transmit an optical coherence tomography signal.

In general, in one embodiment, a drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft includes a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein. The drive assembly includes a first optical connection configured to connect the stationary fiber with a light source. The drive assembly includes a motor configured to rotate the rotatable portion of the fiber optic rotating junction. The motor has a hollow shaft configured to house a portion of the fiber optic rotating junction such that the motor and the fiber optical rotating junction are coaxial. The drive assembly includes a second optical connection configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter.

This and other embodiments can include one or more of the following features. The rotatable fiber of the fiber optic junction can be housed within the hollow shaft. The drive assembly can further include a locking mechanism that can be configured to lock a handle of the imaging catheter to the drive assembly. The stationary and rotatable fibers can be configured to transmit an optical coherence tomography signal.

In general, in one embodiment, a drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft includes a drive assembly housing. The drive assembly further includes a fiber optic rotating junction within the housing having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein. The drive assembly includes a first optical connection through the housing configured to connect the stationary fiber with a light source. The drive assembly includes a motor in the housing configured to rotate the rotatable portion of the fiber optic rotating junction. The drive assembly includes a linear slide in the housing configured to translate the fiber optic rotating junction axially within the housing. The drive assembly includes a second optical connection through the housing configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber and so as to transmit light from the light source to the rotatable fiber of the catheter.

This and other embodiments can include one or more of the following features. The stationary fiber of the fiber optic rotating junction can be axially fixed at the first optical connection. The stationary fiber of the fiber optic rotating junction can include slack configured to account for translation of the fiber optic rotating junction. The drive assembly can further include a locking mechanism that can be configured to lock a handle of the imaging catheter to the drive assembly. The stationary and rotatable fibers can be configured to transmit an optical coherence tomography signal.

In general, in one embodiment, a drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, includes a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein. The drive assembly includes a first optical connection configured to connect the stationary fiber with a light source. The drive assembly includes a motor configured to rotate the rotatable portion of the fiber optic rotating junction. The drive assembly includes a second optical connection configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter. The drive assembly includes a magnetic locking mechanism configured to automatically align the second optical connection with the drive shaft and the rotatable fiber of the imaging catheter.

Methods of using these drive systems are also described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

FIG. 1A shows a variation of the drive assembly configured to drive an imaging catheter with a rotary cutter. The drive assembly includes a motor to drive the catheter cutter and a linear slide assembly to translate an optical assembly with a drive shaft. FIG. 1B shows the drive assembly with the outer housing removed to exhibit the interior components.

FIG. 2 A shows a handle lock of the drive assembly of FIGS. 1A and 1B. FIG. 2B shows an exploded view of the drive assembly of FIG. 2A.

FIG. 3A shows the interaction between the handle lock of FIG. 2A and a catheter handle. FIG. 3B shows the handle lock of FIG. 2A in an open position. FIG. 3C shows the handle lock of FIG. 2A in a closed position.

FIGS. 4A and 4B show the rotary optical drive subassembly of the drive assembly of FIGS. 1A and 1B.

FIG. 5A shows activation of the linear slide of the rotary optical drive subassembly of FIGS. 4A and 4B in a tissue packing position. FIG. 5B shows activation of the linear slide of the rotary optical drive subassembly of FIGS. 4A and 4B in a tissue cut position.

FIG. 6 shows the outer housing of another exemplary drive assembly.

FIGS. 7 and 8 show the drive assembly of FIG. 6 with the housing removed to show the inner components and subassemblies.

FIGS. 9A and 9B show a close-up of the distal portion of the drive assembly shown in FIGS. 7 and 8, including the locking mechanism to connect a handle to the drive assembly of FIG. 6.

FIG. 10 is a top view of the locking mechanism of FIGS. 7 and 8.

FIGS. 11A and 11B show front and side view of the locking mechanism of FIGS. 7 and 8.

FIGS. 12 and 13 show the drive assembly of FIGS. 7 and 8, including an exemplary rotary optical drive assembly.

FIGS. 14A and 14B show a close-up of an optical sensor configured to align a drive assembly (such as the drive assembly of FIGS. 7 and 8) with a catheter or catheter handle.

FIG. 15 shows an axial view of a handle lock of the drive assembly of FIGS. 7 and 8 with the optical connector aligned in top-dead-center position.

FIG. 16 shows a magnetic connector for connecting a catheter to a drive assembly.

FIG. 17 shows another exemplary drive assembly.

FIGS. 18A-18C show the drive assembly of FIG. 17 with the housing removed.

FIG. 19 is a cross-sectional diagrammatic view of the rotary optical drive subassembly of FIGS. 18A-18C.

DETAILED DESCRIPTION

Described herein are reusable drive assemblies configured to be attached to an imaging catheter, such as an atherectomy catheter. In general, the drive assemblies can include a motor to rotate both a drive shaft of the catheter and a rotating fiber of the catheter. The drive assemblies herein can further include an optical pass-through to transfer light from a light source to the rotating fiber of the catheter, such as for optical coherence tomography (OCT) imaging. The optical pass-through can include a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein. The drive assembles can be configured to attach at the proximal end to a light source and at the distal end to a catheter.

In some embodiments, a drive assembly can be configured to provide rotation of a drive shaft, simultaneous rotation of an optical fiber, translation of the drive shaft, and simultaneous translation of the fiber. Such drive assemblies could be used, for example, with a catheter having an imaging sensor and a cutter that are driven by the same drive shaft where the drive shaft can be translated proximally or distally to pack tissue and/or expose the cutter.

For example, referring to FIGS. 1A-5B, a drive assembly 100 can be configured to provide rotation of a drive shaft, rotation of an optical fiber, translation of the drive shaft, and translation of the fiber of an imaging catheter.

As shown in FIGS. 1A-1B, the drive assembly 100 can include a housing 101 (having an access door 107 therein) and a handle lock 103, to connect the drive assembly 100 to a

As shown in FIGS. 1A-1B, the drive assembly 100 can include a housing 101 (having an access door 107 therein) and a handle lock 103, to connect the drive assembly 100 to a catheter handle. As shown in FIG. 1B, the drive assembly 100 can further include a rotary optical drive subassembly 102 configured to provide rotation to the drive shaft and optical fiber of a catheter and a linear slide subassembly 104 configured to provide translation of the drive shaft and optical fiber of the catheter used with the drive assembly 100. The drive assembly 100 can be connected at a proximal end to the light source. A power source can connected to the drive assembly 100 to provide the driving power. A power button 109 can be used to turn the power to turn the drive assembly 100 on and off.

The handle lock 103 can provide a mechanical interface to secure the catheter handle to the drive assembly 100 during use. In one embodiment, as shown in FIG. 2B, the handle lock 103 can include a core 220, two retaining arms 224, and a release button 228 (the release button is also shown in FIG. 1A). The handle lock core 220 can include mating features 229 thereon configured such that the core 220 can mate with the proximal end of the catheter handle and enclose the proximal end of the catheter handle and limit radial handle movement. Axial movement of the catheter handle can be limited by the retaining arms 224 once the handle is fully seated in the lock 103.

Referring to FIG. 3A, to engage the retaining arms 224, the handle of the catheter can be inserted into the handle lock 103 such that features of the handle (such as mating wings) fit within the mating keyways 229 of the core 220, thereby allowing for self-alignment of the handle with the drive assembly 100. Once inserted, the handle can push the retaining arms 224 into the open position, as shown in FIG. 3B. After the mating features of the handle, such as wings, pass fully through the retaining arms 224, an extension spring 227 in the handle lock 103 can cause the retaining arms 224 to return to a closed position (see FIG. 3C), preventing the catheter and catheter handle from moving axially and rotationally within the sled. After use, the catheter or catheter handle can be removed from the drive assembly 100 by pushing down on the handle release button 228, which can cause the retaining arms 224 to rotate into the open position, thereby allowing the catheter handle to be removed from the handle lock 103.

Referring to FIG. 4A, the rotary optical drive subassembly 102 of the drive assembly 100 can include a fiber optic rotating junction (FORJ) 442, a motor 444, an optical connector 446, which can be connected to the drive shaft (and optical fiber) of the catheter, and an optical connector 447, which can connected to the light source. The FORJ 442 can advantageously serve to provide an optical link between light from a light source and the optical fiber of the catheter. The FORJ 442 can further advantageously serve to decouple the catheter fiber rotation from light source fiber rotation, i.e., can provide a junction for the catheter's rotating optical fiber and a static optical fiber from the light source. In one embodiment, the motor 444 can be a DC brushless motor with integrated speed controller. In use, the motor 444 can be configured to drive the FORJ through a belt-pulley system. In turn, the FORJ 442 can be configured to drive the rotation of the drive shaft and optical fiber of the catheter through the optical connector 446, which can connect directly to the drive shaft.

Thus, referring to FIG. 4B, the motor 444 and the FORT 442 can have pulleys 445, 443, respectively, that can be connected by a belt (not shown). As the motor 444 turns (shown by arrow B), the FORT 442 turns (shown by arrow C). The FORJ 442 can be rigidly connected to the distal optical connector 446 through mechanical couplings. Therefore, as the FORT 442 turns, the optical connector 446 turns. When the catheter handle is attached, the distal optical connector is mechanically locked to the catheter optical connector, which is connected to the drive shaft and optical fiber of the catheter. Therefore, as the distal optical connector 446 rotates, so does the catheter drive shaft and optical fiber.

Referring to FIGS. 5A and 5B, the linear slide subassembly 104 includes a linear slide 552 having a stationary portion 554 connected to the housing 101 of the drive assembly 100 and a translatable portion 556 movable relative to the housing 101 of the drive assembly. The rotary optical drive subassembly 102 can rest on, and be fixedly attached to, the translatable portion 556 of the linear slide 552. As a result, the rotary optical drive subassembly 102 can slide axially (proximally and distally) relative to the stationary portion 554 of the linear slide 552 (and thus relative to the housing 101), as shown by the arrow A in FIG. 5A. The linear slide assembly can thus translate axially in concert with axial movement of the catheter's drive shaft and optical fiber (such as for exposing the cutter or packing the nosecone). Thus, as shown in FIGS. 5A and B, if the drive shaft and thus the cutter need to be moved distally (FIG. 5A) and/or proximally (FIG. 5B), such as to activate the nosecone or cutter deflection and/or pack tissue into the nosecone, the rotary optical subassembly 102 can move simultaneously, thereby maintaining the optical connection between the catheter and the light source.

The linear slide can include a space for slack in the optical fiber therein. For example, slack in the optical fiber can coil around within the inner perimeter of the housing 101. The slack in the optical fiber can ensure that movement of the rotary optical subassembly 102 distally will not pull the optical fiber out of the optical connection 447 with the light source (as the optical fiber can be axially fixed at the optical connection 447).

In some embodiments, movement of the rotary optical subassembly 102 can be activated through the optical connection 446 via an activation mechanism on the handle or the catheter. Thus, the rotary optical subassembly 102 can be passively moved as the parts of the catheter or handle are actively moved. A release lever 145 can be configured to either allow or

The axial translation of the rotary optical drive assembly 104 and the drive shaft can occur relative to the sled housing 101 and the catheter outer shaft and handle (connected to the housing 101), all of which can remain stationary. Maintaining a stationary outer shaft ensures that the outer shaft can remain axially and rotationally stabilized in the vessel while the cutter deflection and/or tissue packing occur, thereby ensuring that the physician does not lose the desired catheter position relative to the vessel.

The drive assembly 100 can advantageously provide a therapeutic amount of torque to the drive shaft/cutter of a catheter while also providing the required speed of rotation for imaging, such as OCT imaging. For example, the drive assembly 100 can provide 0.5 to 15 ounce inches of torque, such as 0.5 to 10 ounce inches, such as 1 to 5 ounce inches, such as approximately 2 ounce inches of torque.

In some embodiments, a drive assembly can be configured to provide only rotation of a drive shaft and simultaneous rotation of an optical fiber (and not translation of either). Such drive assemblies could be used, for example, with: (1) a catheter having an imaging sensor and a cutter that are driven by the same drive shaft where the drive shaft can be translated proximally or distally to pack tissue and/or expose the cutter (and where the translation mechanism is provided in the handle); or (2) a catheter having a separately rotatable imaging and cutting shaft.

For example, the drive assembly 100 described above can be used without the linear drive subassembly 102 to provide only rotation. Another drive assembly 1400 is shown with respect to FIGS. 6-15 that can be configured to provide rotation of a drive shaft and rotation of an optical fiber of an imaging catheter.

Referring to FIGS. 6-8, the drive assembly 1400 can include a housing 1402 having a rotary optical subassembly 1411, a control board (not shown), and a position sensor 1433 therein. The drive assembly 1400 can further include a connection 1401 to a cable 1403 extending to the light source as well as a handle lock 1405 to connect to a catheter handle. A power button 1407 on the housing 1402 can be used to toggle power to the drive assembly 1400.

Referring to FIGS. 9A-11B, the handle lock 1405 can be a mechanical interface which secures a catheter handle of an imaging catheter to the drive assembly 1400 during use. The handle lock 1405 can include a core 1407 to limit radial handle movement by encircling the proximal end of the catheter handle. The core 1407 can be held in place in the drive assembly 1400 by mating features 1409 at the top and bottom of the housing 1402. The catheter handle can be locked in its axial position by a handle lock bar 1411 that is loaded with a spring 1413. To lock the handle into the drive assembly 100, mating feature (such as a wing) on the handle is aligned with a mating keyway 1417. When inserting the catheter into the drive assembly, the keyway 1415 on the handle initially aligns the spring-loaded handle lock bar boss 1419 with the aligned with a mating keyway 1417. When inserting the catheter into the drive assembly, the keyway 1415 on the handle initially aligns the spring-loaded handle lock bar boss 1419 with the keyway 1417, thereby allowing g for self-alignment of the handle with the drive assembly 1400. As the handle is inserted further, the handle lock bar boss 1419 eventually slides into a locking channel 1421 on the handle, securing the handle position. To release the handle, the user pushes the handle release button 1423, which can be attached to the handle lock bar 1411. As a result, the handle lock bar 1411 slides back into alignment with the keyway 1417, allowing the handle to be removed. Movement of the handle lock bar 1411 and button 1423 is otherwise restrained by the housing 1402.

Referring to FIGS. 12-13, the rotary optical subassembly 1411 includes a fiber optic rotating junction (FORJ) 1421 and a motor 1432, such as a DC brushless motor with integrated speed control. The rotary optical subassembly 1411 can be designed similar to the rotary optical subassembly 102 described above and can thus serve to both: (1) decouple the catheter fiber rotation from the source of rotation; and (2) drive the catheter's cutting and imaging elements through the optical connector 1427. The motor 1432 drives the FORJ 1421 through pulleys 1431, 1435 which are connected by a belt (not shown). In turn, the FORJ 1421 drives the rotation of the drive shaft and optical fiber of the catheter through the optical connector 1427.

The drive assembly 1400 can further include an automatic alignment feature to align the catheter properly with respect to the drive assembly 1400. Cleaving the optical fiber of the catheter and the optical fiber of the drive assembly at an angle (e.g. 8 degrees) is desirable to reduce back-reflection at the interface between the optical fibers. Immediate physical connection is also desirable to reduce transmission losses. As such, the optical fibers should be aligned at exactly the right orientation (with the angled cleaves lined up) to allow the light to travel from one optical fiber). If an automatic alignment feature is created to properly orient these fibers with respect to one another, then the separate step of manually connecting the optical assemblies of the catheter/handle and the drive assembly can be eliminated.

For example, referring to FIGS. 14A-14B, the drive assembly 1400 can be automatically aligned with the catheter handle through alignment mechanisms on both the drive assembly 1400 and on the catheter handle. Thus, in one embodiment, the drive assembly 1400 can include an orientation sensor 1433 configured to sense the rotational position of the optical connector 1427. For example, as shown in FIGS. 14A-14B, the sensor 1433 can be a slot sensor (or optical fork sensor) configured to detect a flag 1442 on the optical connector 1427. The sensor 1433 (in this case, a slot sensor) can thus detect as the flag 1442 passes therethrough. Because the flag 1442 is in a set position relative to the connection mechanisms of the optical connector 1427, the detection of the flag 1442 can allow for the determination of the rotational position or orientation of the connection mechanisms.

When the user powers the drive assembly 1400 off, a control board in the drive assembly 1400 can use feedback from the optical sensor 1433 to stop the motor 1432 such that the optical connector 1427 is always in the same position, such as the top-dead center position shown in FIG. 15. That is, after the user powers the drive assembly 1400 off, the control board can keep the motor 1432 and FORJ 1421 running at a constant speed until the exact position of the optical connector 1427 is identified based upon readings from the sensor 1433. The control board can then cut power to the motor such that, based upon the sensed position and the known length of time that the FORJ takes to stop after power is cut, the optical connector 1427 will stop in a predetermined position. The predetermine position can be the same every time that the drive assembly 1400 is used.

Advantageously, if the optical connector 1427 always stops in the same position, it can mate with a handle or catheter that is preset in a corresponding mating optical position (such as set by the manufacturer). Such a feature can provide for an automatic optical connection when the drive assembly is physically attached to the catheter or handle in a set orientation, such as with the locking mechanism described above. In some embodiments, the physical relationship between the drive assembly 1400 and the handle or catheter can be set, such as with a mating tooth (e.g. a protruding tooth or rib on the drive assembly and a recessed slot on the catheter handle).

Advantageously, the drive assembly 1400 can be less than 3 lbs, such as less than 2 lbs, such as approximately 1.5 lbs in weight. Further, the drive assembly can be less than 90 cubic inches, such as less than 75 cubic inches, such as less than 65 cubic inches, for example approximately 63 cubic inches in volume. In one embodiment, the drive assembly 1400 can measure 9″ by 3.5″ by 2″.

Another drive assembly 1700 is shown with respect to FIGS. 17-19 that can be configured to provide rotation of a drive shaft and rotation of an optical fiber of an imaging catheter.

Referring to FIG. 17, the drive assembly 1700 can include a housing 1701, an optical connector 1721 configured to connect the drive assembly 1700 to a light source, a power connector 1723 configured to connect the drive assembly 1700 to a power source, and a connection 1755 (such as the handle locks described above) configured to connect the drive assembly 1700 to a handle 900 of an imaging catheter.

As shown in FIG. 18A-19 the drive assembly 1700 can include a rotating optical drive subassembly 1811 including a FORJ 1813, a motor 1815, and an optical connector 1817, such as an MU adaptor, configured to connect the FORT with the catheter drive shaft and optical fiber. The shaft of the motor 1815 can be hollow so as to allow the FORJ 1813 to extend therethrough (i.e., the motor 1815 and the FORJ 1813 can be coaxial). In one embodiment, as shown in FIG. 19, the FORT 1813 is entirely on the stationary side of the motor, with only a rotating fiber 1993 passing through the motor 1815. In another embodiment, the FORT 1813 works through the motor 1815, with a stationary fiber on one side, light passing through the hollow shaft, and a rotating fiber on the far side. In yet another embodiment, the FORT 1813 is on the rotating side of the motor 1815 and a stationary fiber inside a stationary tube passes through the motor 1815. The motor 1815 can further be configured to provide sufficient torque without gearing. Further, the connector 1817 can be configured to as to minimize the moment of inertia and swept volume to reduce vibration.

Advantageously, by having the motor 1815 and the FORT 1813 coaxial, the dimensions of the drive assembly 1700 can be reduced. For example, the drive assembly 1700 can have a volume of less than 40 cubic inches, such as less than 20 cubic inches, such as less than 18 cubic inches, such as approximately 14-16 cubic inches. Further, the drive assembly 1700 can have a length of less than or equal to nine inches and a diameter of less than or equal to 2.5 inches, such as approximately 1.25 inches. In exemplary embodiments, the drive assembly 1700 is approximately 9″ long by 1.5″ in diameter, 9″ long by 1.25″ in diameter, or 7″ long by 1.25″ in diameter.

Like the other drive assemblies described herein, when motor 1815 rotates, the FORJ 1813 can rotate, thereby causing the optical connector 1817 (and thus the drive shaft and optical fiber of the imaging catheter) to rotate. Further, similar to the drive assembly 1400, the drive assembly 1700 can include a mechanism for automatically/mechanically aligning the drive assembly 1700 with the handle or catheter, such as a top dead center sensor.

Referring to FIG. 19, it is to be understood that the FORJ 1815 (and any FORJ described herein) can include a rotating portion 1991 with a rotating fiber 1993 and a rotating lens 1995 and a stationary portion 1997 with a stationary fiber 1998 and a stationary lens 1999.

Referring to FIG. 16, in some embodiments, the drive assemblies described herein can include a magnetic handle locking assembly 2000 in place of the locking mechanisms described above. The locking assembly 2000 can be configured to mate with a magnetic assembly 2050 on the catheter handle.

In one embodiment, shown in FIG. 16, the locking assembly 2000 can include a magnetic housing 2002 and a female fiber optic connector 2004, such as an FC-APCC, which can be configured to mate with a catheter magnetic housing 2052 and a male fiber optic connector 2054, such as an FC-APC 2054 (though in other embodiments, the positions of the female/male FC-APCs could be reversed). The housings 2002, 2052 can include slots 2006 a,b and 2056 a,b configured to hold magnets therein. The magnets in each slot 2006 a,b of the drive assembly can be of opposite polarity to one another. Further, the magnets in slots 2006 a,b can be of opposite polarity to the magnets in the adjacent catheter locking assembly (e.g., magnets in slot 2006 a can be of opposite polarity to magnets in slot 2056 a). Thus, if the magnetic assemblies 2000, 2050 are not properly aligned, the opposing polarities of the magnets can cause the assemblies 2000, 2050 to rotate into the proper alignment, thus providing an automatic alignment feature for the drive assemblies described herein with a corresponding imaging catheter handle.

The locking assembly 2000 can further include mechanical teeth and mating slots 2063 a,b therein configured to hold the magnetic assemblies 2000, 2050 together as one or the other is rotated, thereby transmitting torque from one assembly 2000 to the other 2050.

Advantageously, the magnetic handle locking assembly 2000 can allow insertion of the catheter into the drive assembly with a single hand without requiring a secondary fiber connection, in contrast to other drive assemblies where the optical connection was manually made after the mechanical connection was made.

The drive assemblies described herein can be reusable, advantageously reducing the cost and complexity associated with imaging catheters.

Further, the drive assemblies described herein can advantageously be introduced into the sterile field through use of a sterile bag. For example, a non-sterile operator, using sterile technique, can open the sterile bag pouch and present the sterile bag to the sterile operator. The sterile operator can remove the bag from the sterile pouch and pass the catheter handle through the sterile bag. The non-sterile operator can then present the drive assembly 100 to the sterile operator. The sterile operator can connect the catheter handle into the handle lock until the catheter is locked into place. The non-sterile operator can connect the optical connector 446 to the catheter and close the access door 107 of housing 101. The non-sterile operator can further grab the outside of the bag and pull the bag back over the drive assembly and attached cables. Finally, the sterile operator can position the bagged drive assembly in the sterile field where desired. The drive assembly can be activated through toggling of the power switch. Similar methodologies can be used with the drive assemblies 1400 and 1700 described herein, though the automatic optical connection between the drive assemblies 1400 and 1700 advantageously eliminates the step of creating a separate optical connection (such as by opening the access door 107 of the drive assembly 100).

It is to be understood that any of the features of the various exemplary drive assemblies described herein could be substituted or added to other drive assemblies while still lying within the scope of this disclosure.

The drive assemblies described herein can be used to transmit light from a source, such as for optical coherence tomography. Exemplary imaging systems that can be used with the drive assemblies are described in copending patent applications: U.S. patent application Ser. No. 12/790,703, titled “OPTICAL COHERENCE TOMOGRAPHY FOR BIOLOGICAL IMAGING,” filed May 28, 2010, Publication No. US-2010-0305452-A1; U.S. patent application Ser. No. 12/829,267, titled “CATHETER-BASED OFF-AXIS OPTICAL COHERENCE TOMOGRAPHY IMAGING SYSTEM,” filed Jul. 1, 2010, Publication No. US-2010-0021926-A1; and International Patent Application titled “OPTICAL COHERENCE TOMOGRAPHY WITH GRADED INDEX FIBER FOR BIOLOGICAL IMAGING,” filed herewith, all of which are incorporated by reference in their entireties.

The drive assemblies described herein can be used with a variety of different catheters, such as atherectomy catheters with imaging. Exemplary catheters and/or handles that can be used with the drive assemblies described herein are set forth in copending patent applications: U.S. patent application Ser. No. 12/829,277, titled “ATHERECTOMY CATHETER WITH LATERALLY-DISPLACEABLE TIP,” filed Jul. 1, 2010, Publication No. US-2011-0004107-A1; U.S. patent application Ser. No. 13/175,232, titled “ATHERECTOMY CATHETERS WITH LONGITUDINALLY DISPLACEABLE DRIVE SHAFTS,” filed Jul. 1, 2011, Publication No. US-2012-0046679-A1; U.S. patent application Ser. No. 13/654,357, titled “ATHERECTOMY CATHETERS AND NON-CONTACT ACTUATION MECHANISM FOR CATHETERS,” filed Oct. 17, 2012; U.S. patent application Ser. No. 13/675,867, titled “OCCLUSION-CROSSING DEVICES, ATHERECTOMY DEVICES, AND IMAGING,” filed Nov. 13, 2012; International Patent Application titled “ATHERECTOMY CATHETERS WITH IMAGING,” filed herewith; and International Patent Application titled “BALLOON ATHERECTOMY CATHETERS WITH IMAGING,” filed herewith, all of which are incorporated by reference in their entireties.

Additional details pertinent to the present invention, including materials and manufacturing techniques, may be employed as within the level of those with skill in the relevant art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts commonly or logically employed. Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein. Likewise, reference to a singular item, includes the possibility that there are a plurality of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “and,” “said,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Unless defined otherwise herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The breadth of the present invention is not to be limited by the subject specification, but rather only by the plain meaning of the claim terms employed.

When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.

Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

Although the terms “first” and “second” may be used herein to describe various features/elements, these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.

As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. 

What is claimed is:
 1. A drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, the drive assembly comprising: a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein; a first optical connection configured to connect the stationary fiber with a light source; a motor configured to rotate the rotatable portion of the fiber optic rotating junction; a second optical connection configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter; a sensor configured to detect a rotational position of the fiber optic rotating junction; and a processor configured to obtain the detected rotational position and stop the motor only when the fiber optic rotating junction is in a predetermined rotational position.
 2. The drive assembly of claim 1, wherein the sensor is a slot sensor configured to detect a flag on the fiber optic rotating junction.
 3. The drive assembly of claim 1, further comprising a locking mechanism configured to lock a handle of the imaging catheter to the drive assembly.
 4. The drive assembly of claim 3, wherein the locking mechanism includes mechanical features to physically align the handle with respect to the drive assembly.
 5. The drive assembly of claim 4, wherein the locking mechanism is configured such that physical alignment of the catheter handle with respect to the drive assembly further aligns an optical connection of the handle with the predetermined rotational position of the fiber optic rotating junction.
 6. The drive assembly of claim 1, wherein the stationary and rotatable fibers are configured to transmit an optical coherence tomography signal.
 7. A method of driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, the method comprising: connecting a stationary fiber of a stationary portion of a fiber optic rotating junction in a drive assembly with a light source; connecting a rotatable fiber of the fiber optic rotating junction with the drive shaft and the rotatable fiber of the imaging catheter; rotating the rotatable portion of a fiber optic rotating junction with a motor in the drive assembly such that both the drive shaft and the rotatable fiber of the imaging catheter rotate and such that light is transmitted from the light source to the rotatable fiber of the imaging catheter; sensing a position of the fiber optic rotating junction; and stopping the motor based upon the sensed position only when the fiber optic rotating junction is in a predetermined rotational position.
 8. The method of claim 7, wherein the position is sensed with a slot sensor.
 9. The method of claim 7, further comprising locking a handle of the imaging catheter into the drive assembly.
 10. The method of claim 9, wherein the locking mechanism includes mechanical features to physically align the catheter handle with respect to the drive assembly.
 11. The method of claim 10, wherein locking the handle of the imaging catheter into the drive assembly using the mechanical features aligns an optical connection of the handle with the predetermined rotational position of the fiber optic rotating junction.
 12. The method of claim 11, further comprising transmitting an optical coherence tomography signal through the stationary and rotatable fibers.
 13. A drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, the drive assembly comprising: a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein; a first optical connection configured to connect the stationary fiber with a light source; a motor configured to rotate the rotatable portion of the fiber optic rotating junction, the motor having a hollow shaft configured to house a portion of the fiber optic rotating junction such that the motor and the fiber optical rotating junction are coaxial; and a second optical connection configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter.
 14. The drive assembly of claim 13, wherein only the rotatable fiber of the fiber optic junction is housed within the hollow shaft.
 15. The drive assembly of claim 13, further comprising a locking mechanism configured to lock a handle of the imaging catheter to the drive assembly.
 16. The drive assembly of claim 13, wherein the stationary and rotatable fibers are configured to transmit an optical coherence tomography signal.
 17. A drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, the drive assembly comprising: a drive assembly housing; a fiber optic rotating junction within the housing having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein; a first optical connection through the housing configured to connect the stationary fiber with a light source; a motor in the housing configured to rotate the rotatable portion of the fiber optic rotating junction; a linear slide in the housing configured to translate the fiber optic rotating junction axially within the housing; and a second optical connection through the housing configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber and so as to transmit light from the light source to the rotatable fiber of the catheter.
 18. The drive assembly of claim 17, wherein the stationary fiber of the fiber optic rotating junction is axially fixed at the first optical connection.
 19. The drive assembly of claim 17, wherein the stationary fiber of the fiber optic rotating junction includes slack configured to account for translation of the fiber optic rotating junction.
 20. The drive assembly of claim 17, further comprising a locking mechanism configured to lock a handle of the imaging catheter to the drive assembly.
 21. The drive assembly of claim 17, wherein the stationary and rotatable fibers are configured to transmit an optical coherence tomography signal.
 22. A drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, the drive assembly comprising: a fiber optic rotating junction having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein; a first optical connection configured to connect the stationary fiber with a light source; a motor configured to rotate the rotatable portion of the fiber optic rotating junction; and a second optical connection configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter; and a magnetic locking mechanism configured to automatically align the second optical connection with the drive shaft and the rotatable fiber of the imaging catheter.
 23. A drive assembly for driving an imaging catheter having a rotatable fiber and a rotatable drive shaft, the drive assembly comprising: a drive assembly housing; a fiber optic rotating junction within the housing having a stationary portion with a stationary fiber therein and a rotatable portion with a rotatable fiber therein; a first optical connection through the housing configured to connect the stationary fiber with a light source; a motor within the housing configured to rotate the rotatable portion of the fiber optic rotating junction; and a second optical connection through the housing configured to connect the rotatable portion of the fiber optic rotating junction with both the drive shaft and the rotatable fiber of the imaging catheter so as to transmit torque from the motor to the drive shaft and the rotatable fiber of the catheter and so as to transmit light from the light source to the rotatable fiber of the catheter; wherein the housing is less than 75 cubic inches in volume, and wherein the drive assembly has a total weight of less than 2 pounds.
 24. The drive assembly of claim 23, wherein the volume is less than 40 cubic inches.
 25. The drive assembly of claim 24, wherein the volume is less than 20 cubic inches.
 26. The drive assembly of claim 23, further comprising a locking mechanism configured to lock a handle of the imaging catheter to the drive assembly.
 27. The drive assembly of claim 23, wherein the stationary and rotatable fibers are configured to transmit an optical coherence tomography signal. 